Method of manufacturing silk stockings



United States Patent 2,774,232 Patented Dec. 18, 1956 "ice turns per meter in H4 whereas the nylon fiber has a light twist of 380 per meter in N-12 and 360 per meter 2,774,232 in N-2 so that the raw silk fiber ought to appear consid- METHOD OF MANUFACTURjNG SILK erably fine as compared with nylon fibers. Contrary KI GS 5 to this expectation, the silk fiber has, however, a relatively very thick appearance in comparison with the H1535!" Kaklzakl suwa Nagano Prefecture Japan nylon fiber. This is a great disadvantage of the silk fiber. N0 Drawing Application Mal-ch 5 95 In case when contraction in thin stockings of either Serial No. 214,017 silk or nylon is caused, it is difiicult to arrive again at the original thread or fiber structure due to the twist Claims pnonty,apphcat10n Japan June 9, 1950 imparted thereto. Therefore, it is advisable to prefer 4 Claims 17g fibers with a light twist, but up to now, the method of manufacturing silk stockings required a heavy twist to the fiber because the increased diameter of a bundle ThiS invention relates to method 0f manufacturing Of of raw fibers does not becgme fine without giving a stockings, in particular knitted silk stockings. heavy twist to such fibers.

The T635011 y Silk Stoddngs are Weaker than Ilyloll When all-silk stockings are refined, the rate of restockings results from the fact that in the course of refining of the leg part with coarse mesh of fine raw silk fining Silk the latter remains in l(he State Of The is greater than that of the welt, heel, sole and toe parts bundle of these fibers expands during the treatment to 20 with fin m sh of thick raw ilk. Thus, the leg art is the extent that its apparent diameter becomes larger te r fi ed nd the bundle of fiber heavily expands than actually desired. In other words, ladies who desire to cause the easy generation of contraction. to wear thinner stockings nowadays, cannot resort to If the part of coarse mesh can be refined as well as silk stockings made from very thin fibers due to the the part of fine mesh at the same rate, the leg part will particular structure of the raw silk. As the raw silk is not be too refined. Consequently, theobject of the generally made up from several cocoon threads eminvention is to obtain the rate of refining by means of bracing one another, the outer appearance thereof seems heretofore known. treatment of raw fibers for the leg to be comparatively fine. part with formalin or other chemicals to lower the solu- However, if such raw silk is refined, sericin is removed bility of sericin. Further, it is contemplated according and its increased diameter not only becomes from 1.3 to to the invention to more eifectively produce silk stockl.5 times the diameter of raw silk but also the cocoon ings having equal durability to nylon stockings whereby threads composed of two fibroin fibers closely adhered the diameter of a bundle of fibers in silk stockings reby sericin separate from each other upon removal of mains constant as tothe magnitude of raw silk fibers. sericin, and therefore raw silk will generally be com- If the process according to-the invention is carried posed of very fine fibroin fibers only. Particularly in out along the above outline, that is to say, if silk stockcase of thin silk stockings contraction of the fibers often ings are refined after knitting operation by the use of occurs which causes easy breakage of and damage to raw silk for entire parts of welt, heel, sole and toe, and silk stockings. This is one of the reasons why a run raw silk previously treated to fix sericin for the leg part, occurs more easily with silk stockings than with nylon .the result is obtained that the leg part remains in the stockings. 40 same state of raw silk whereas the welt, heel, sole and The following table shows the comparison of the actual toe parts become elastic and flexible due to the removal diameter with the increased diameter of a bundle of raw of sericin by a degumming operation. fibers used in silk stockings and nylon stockings, which Therefore, the raw silk fiber assumes substantially will give an idea why silk stockings hitherto manufactured mass quality equal to that of the nylon fiber. Thus silk are relatively weak. stockings as thin as possible may now be produced.

Table I Actual di- Increased Kind of amcter of diameter Deniers Marks Mateabundle ofabun- Bill) of raw No. of twist per meter rials of raw fidle of raw fibers bars, D in fibers, D1

1111010115 mmicrons 83.5 128.0 1.525 42 600, clockwise. N12 Nylon 91.4 127.0 1.390 51 380, counterclockwise. H4 Si1k 100.0 150.0 1.500 1,300 clockwise. 1,500

counterclockwise. N-2. Nylon" 112.0 150.0 1. 340 63 360, counterclockwise.

Nora-In the above items a bundle of raw fibers part of stockings.

In Table I, F-7 and N-12 or H-4 and N-2 designate respectively stockings having approximately the same appearance of thinness. Comparing two pairs of stockings of each kind, it will be seen that the deniers of nylon are 51 in N-l2 or 63 in N-2 whereas the deniers of silk are 42 in F-7 or 56 in H-4, that is, the actual diameter of a bundle of fibers of nylon stockings is always larger than that of silk stockings. This is one of the reasons why nylon stockings are stronger than silk stockings. For the purpose of comparison, the silk fiber has a heavy twist of 600 per meter in F-7 and 1,500

means raw. fibers used for the leg In short, this invention relates to a method of manufacturing silk stockings which is characterized by knitting them from raw silk which is previously treated to fix sericin for the leg part and to soften the fibers employed for the welt, heel, sole and toe parts. Several ways suitable for carrying out the process described above are given in the following examples.

For shortness sake hereafter the welt, heel, sole and toe parts are described as A and the leg part as B.

Example 1.-Ordinary raw silk is used for A and raw silk previously treated to fix sericin for B. After knitting only sericin of A is removed.

Example 2.Raw silk previously refined about seventy percent is-used for A and ordinary raw silk for B. After knitting raw silkfor A- is slightly. softened. M

Example 3.Rawsilk of fibroin fibers only by previously refining is used for A and; silk which is suitably twisted andpreviously treated to fixsericin-fonB. After knitting raw silkfibers are finished-before or after dyeing without special refining;

Example 4-.Nylon, Vinyon (of the formula cotton, artificial silk, staple fiber: or other soft'fibers as well! as silk which is suitably twisted and previously treated to fix sericingare'usedfor A, and soft raw silk fibers having the same diameter of a bundle of fibers as that of raw silk and the smallincreased diameter by means of refining. rawsilk previously. in such a degree thatdefects do not appear, i. e., 50% refiningto remove about of sericin' andafterward treatment to fix sericin, or silk which is suitably twisted and previously treated to fix sericin, are'used for B, and then stockings are knitted.

Example 5.By. combining'raw silk fibers for B described in Example 4 with each ofraw fibers for A described in Examples 1 to 4, silk stockings are knitted from these fibers;

The result of experiment onthe stockings produced by the process described-in Example'l is shown in'the following table:

a heavy twist of 1,400 per meter. It is known that contraction occurs in silk stockings rather than in nylon stockings whereby in silk stockings contraction causes always a run. However, there seldom occurs contraction in the stockings manufactured according to the method of this invention, because the bundle of fibers remain in the same state of raw silk even if refined and when washed after knitting in view of the treatment to fix sericin. Therefore, so called run-proof silk stockings cari be obtained according to the invention.

Having thus described the invention, What is claimed as newand'desired'to be secured by-'Letters Patent, is:

l. The method of manufacturing hose substantially from raw silkfibers; comprising the stepsof'knitting raw silk fibers previously treated to fix sericin therein to thereby obtain a'm'ajor part of said hose, and then knitting previously degummed raw silk fibers to attain the remainder of said'hose, whereby said remainder of said hose presents elasticity and flexibility relatively higher than said major partof said hose.

2. The method of manufacturing hose substantially from r aw silkfibers, comprising the steps of knittingraw silk fibers previously treated to fix sericin therein to thereby-obtain the legpart of said hose, then knitting raw silk fibers toattain'the' remainder of said'hose, and finally removing sericin from said latter raw silk fibers by degumming operation, whereby. said remainder of said hose presents elasticity and flexibility relatively higher than saidleg .part of said hose.

3: The method of-manufacturing"a knitwear product, comprising the steps of knitting raw silk fibers, prenanny-"treated to fix'sericin'there'in to thereby obtain a Table 11 Actual (11- Increased anieter of' diameter Deniers p Marks Kind of No. of filaabundle of a bun- D1/D of raw No. of Twist per meter fibers ments of fibers, die of fifibers D inmlhers, D1

crops in microns N Nylon 10' 77. 5 87.5; 1. 130 43.4 1,400: K-G Silk 16 80.4 88.7 1. 102 45.;0, Without twist. v F-lfi Silk 30 75.0 114. 0- 1.520 42.0 1,300 counterclockwise.

1,600 clockwise.

NOTE:

1. F-lfi is ordinary silk'stoekings and'K-fi'silk stockings' produced'by the process of this-invention: 2. N 0. of filaments per meter ot K-6,'i. e: 16,-means No; of cocoon threads, because washers are adhered to one piece of sericin.

N-4 and F-l6 are about 43 and their actual diameters of a bundle of fibers are approximately the same. How ever, the actual diameter of a bundle: of silk fibers is 114.0 microns whereas that of nylon fibers is 87.5 microns. Therefore, the ratio of D1 to D of F-16-'-is-l.520"

and of N4 1.130 respectively, and both have the same heavy twist. Comparing K-6 produced by this process with N-4, it will be seen that both have approximately the same apparent diameter of a bundle of fibers, their thicknesses are relatively thin of the same grade, and."

deniers of K-6 are 42, whereas those of N-4 are 4 3'l4f: so that the raw fiber of K-6 has the larger substantial mass than that of N-4. of K-6 is given a suitable twist, it will provide for a larger substantial mass than that of nylonwhich is given It follows that if the raw fiber I References Gited in the file of this patent UNITED STATES PATENTS 2,029,972 Waller-"stein et al. Feb.'4,' 1936 2,040,736 Goodman May 12, 1936 2,503,444 Lawsonet'al; Apr. 11, 1950 

1. THE METHOD OF MANUFACTURING HOSE SUBSTANTIALLY FROM RAW SILK FIBERS, COMPRISING THE STEPS OF KNITTING RAW SILK FIBERS PREVIOUSLY TREATED TO FIX SERICIN THEREIN TO THEREBY OBTAIN A MAJOR PART OF SAID HOSE, AND THEN KNITING PREVIOUSLY DEGUMMED RAW SILK FIBERS TO ATTAIN THE REMAINDER OF SAID HOSE, WHEREBY SAID REMAINDER OF SAID HOSE PRESENTS ELASTICITY AND FLUXIBILITY RELATIVELY HIGHER THAN SAID MAJOR PART OF SAID HOSE. 